BIOM 2000 Lecture Notes - Lecture 2: Acetylcholine, Choroid Plexus, Postganglionic Nerve Fibers

50 views14 pages

goldcrab440

20 Mar 2017

School

Department

Course

Professor

For unlimited access to Class Notes, a Class+ subscription is required.

Document Summary

The inside of the plasma membrane of all cells is more negatively charged compared to the outside. Action potentials (ap) = discharge of the rmp. Have 4 parts: cell body, axon, dendrites, synapses. Some axons are insulated by the myelin sheath which is formed by. In myelinated axons ap are only found at the nodes of ranvier and are moved by a process called saltatory conduction. Involved ap moving from one node to the next. Reduced the angry needed to reinstate the resting potential because not as many sodium potassium pumps are required. Contains vesicles of speci c chemicals called neurotransmitters. Ap at the synapse causes a controlled release of these neurotransmitters. Neurotransmitters are released into the space and bind to receptor proteins on the dendrites of another cell membrane. Contain many extensions from the cell body. Have only one axon and one dendrite. In special sense organs such as the nose and eyes. Rare for the most part: unipolar.

Related Questions

1. The plasma membrane of liver cells contains a glucose uniportthat transports glucose by facilitated diffusion. When the[glucose] is higher inside the liver cell than the [glucose]outside the liver cell, the glucose uniport will

A. couple the transport of glucose out of the cell to thehydrolysis of ATP

B. couple the transport of glucose into the cell to thehydrolysis of ATP

C. switch to a closed conformation, allowing no transport ofglucose

D. transport glucose out of the cell by passive transport

E. transport glucose in of the cell by passive transport

2. Unlike the positive charged ion shown in the middle diagramof figure 11-4B, K+ is higher in concentration inside the cell. Howwill the membrane potential of a cell at rest (shown in both themiddle and right-hand diagrams of Figure 11-4B) affect theelectrochemical gradient for K+?

A. The membrane potential will increase the electrochemicalgradient

B. The membrane potential will decrease the electrochemicalgradient

C. The membrane potential will have no effect on theelectrochemical gradient

3. Which of the following proteins carries out activetransport?

A. gluclose symport

B. Bacteriorhodopsin

C. ABC transporter

D. NA K pump

E. All of the above

4. Aquaporin will not transport Na+ ions because

A. Two asparagine residues in the channel prevent the passage ofNa+ ions by binding the oxygen of each water molecule as it passesby

B. Na+ ions are repelled by the positive charges at the entranceto the channel

C. Na+ ions cannot make contact with the carbonyl (C=O) groupson all four sides of the channel

D. The passage of Na+ ions is energetically unfavorable becauseone side of the channel is hydrophobic in nature

5. The acetylcholine receptor is different from other channelproteins we have discussed, such as the K+ leak channel,because

A. The acetylcholine channel is composed of a single polypeptiderather than multiple subunits

B. The acetylcholine channel transports Na+ ions against theconcentration gradient for sodium

C. The acetylcholine channel has a much smaller diameter thanother channel proteins

D. The acetylcholine channel transports ions with theirassociated shell of water molecules

E. The acetylcholine channel is always open, and never switchesto a closed conformation

6. After opening briefly along the axon of a neuron,voltage-gated ion channels switch to an inactivated conformationthat slowly returns to the original closed conformation of theprotein. This slow change in conformation, requiring about amillisecond, is important because

A. all of the ions that were transported across the membranewhen the ion channels were open must be actively transported backto the other side of the membrane, restoring the originalconcentration gradient, before the ion channels can open again

B. ATP hydrolysis is necessary to drive this energeticallyunfavorable change in conformation

C. it prevents the action potential from reversing direction andtraveling back toward the cell body of the neuron

D. the channel protein must be dephosphorylated in order tocomplete the transport process and return to the originalnonphosphorylated conformation

limeelephant476

1)What type of cell allows the immune system to respond morequickly if the same antigen is encountered a second time?

A)leukocytes

B)memory cells

C)macrophages

D)neutrophils

E)natual killer cells

2)why is the heart divided funtionally into two separate pumpsthat work in series?

A)because arteries carry blood away from the pump and veinsbring blood back to the pump

B)because blood decreases in pressure as it travels throughcirculation

C)because vessles in the vasculature keep blood moving in onedirection'

D)because there are four chambers to the heart

E)none of the above-the heart contracts in unison and is notdivided into two pumps

3)which of the following statements is correct?

A)Na+,K+, Ca2+ and Cl- are all more concentrated in theEXTRACELLULAR fluid

B)Na+, K+, Ca2+ and Cl- are all more concentrated in theEXTRACELLULAR fluid

C)Na+, Ca2+, and Cl- are all more concentrated in theEXTRACELLULAR fluid

D)K+, ca2+ are more concentrated in the EXTRACELLULAR fluid

E)K+, Ca2+ are more concentrated in the EXTRACELLULAR fluid

3)During skeletal muscle contraction:

A)the width of the H-zone decreases

B)the actin heads bind to myosin chain

C)ATP hydrolysis requires Ca2+ as a cofactor

D)tropomyosin changes conformation when Ca2+ binds

E)all of the above occur during skeletal muscle contraction

4)The rapid depolarization phase of myocardial contratile cellaction potential is due to the movement of which ion(s)?

A)Ca2+ flows into the cytosol

B)K+ flow out of the cytosol

C)Na+ flow into the cytosol

D)Ca2+ flow out of the cytosol

E)K+ flow into the cytosol

5)You are a physiology graduate student asked to study theeffect of ion permeability on the initiation of action potentials.You have isolated a cell with resting membrane potential of -70mVand have determined that the cell's threshold voltage is -55mV. Youthen change the cell to make it less permeable to K+ ions(Eions=-90mV)

With all ther condition staying the same, has cell's restingmembrane potential been DEPOLARIZED or HYPERPOLARIZED; and will thecell require a greater or smaller stimulus to reach threshold?

A)hyperpolarize; smaller

B)depolarize;greater

C)hyperpolarize;greater

D)depolarized; smaller

E)none of the above answers are possibe

6)Skeletal muscle cells are UNUSUAL in that they :

A)lack smooth endoplasmic reticulum

B)have no mitochondria

C)depend entirley on anaerobic respiration

D)have MULTIPLE nuclei

E)none of the baove are found in the skeletal muscle cells

7)What is the name for the autonomic nervous system synapses atthe neuroeffector?

A)electrical synapses

B)axon viscosities

C)bidirectional synapses

D)axon varicosities

E)light bulb synapse

8)Which cytokines are involvedin making cells resistant toviruses?

A)colony-stimulating actors

B)interferons

C)erythrpoietin

D)major histocompatibility complex

E)none of the above can make a cell resistant to a virus

9)If a person switiches from normal breathing to more shallowbreathing, whcih statement is true

A)tidal volume decreases

B)alveolar PO2 decreases

C)alveolar ventilation decreases

D)"a" and "b"

E)"a", "b', and "c"

10)Which scenerio supports hyperpolarization of pre-synapticcell?

A)allowing Cl- ions into the cell

B)allowing K+ ions to leave the cell

C)allowing Ca2+ ions into the cell

D)"a" and "b"

E)"a", "b", and "c"

11)The gap junctions in cardia muscle are part of specializedcell junctions that are localized to the__________.

A)transverse tubules

B)intercalated discs

C)Interdigitated fingers

D)desmosomes

E)high-end shppoinf malls

12)What role does myosin light chain kinase (MLCK) play insmooth muscle cell contraction?

A)dephosphorylates myosin

B)phosphorylates actin

C)phosphoylates myosin

D)dephosphorylates actin

E)both "a" and "c"Given that your forearm is 30cm long and yourbiceps inserts 2 cm away from your elbow joint, how much force mustyour biceps exert to hold up a 10kg weight?

A)0.67kg

B)6.0kg

C)20kg

d)150kg

e)600kg

erinbadger748

QUESTION 1

Which of the following is an example of an extracellular signal molecule?

	a.	IP₃
	b.	cAMP
	c.	Insulin
	d.	Diacylglycerol

2 points

QUESTION 2

Nuclear hormone receptors _____

	a.	Bind to water soluble ligands
	b.	Activate second messengers
	c.	Regulate transcription in response to ligand binding
	d.	Are normally located on the plasma membrane

2 points

QUESTION 3

Which of the following does not occur when a receptor tyrosine kinase is bound by ligand?

	a.	Phosphorylation of the RTK
	b.	Cytoplasmic proteins bind the phosphorylated RTK
	c.	Dimerization of the RTK
	d.	The RTK binds to DNA to regulate transcription

2 points

QUESTION 4

Which of these is a logical signal-transduction pathway?

	a.	An intracellular receptor activates phospholipase C, which cleaves a membrane protein to form IP₃, which then activates the opening of an ER channel protein, which releases cyclic AMP into the cytoplasm, where it binds to an intracellular enzyme that carries out a response.
	b.	A G-protein-linked receptor activates G protein, which activates phospholipase C, which cleaves a membrane lipid to form IP₃, which binds to a calcium channel on the ER, which opens to release calcium ions into the cytoplasm, which bind to an intracellular enzyme that carries out a response.
	c.	An ion-channel receptor opens, allowing a steroid hormone to enter the cell; the steroid hormone then activates protein kinases that convert GTP to GDP, which binds to an intracellular enzyme that carries out a response.
	d.	A tyrosine-kinase receptor activates adenylyl cyclase, which activates phospholipase C, which converts ATP into cyclic AMP, which binds to an intracellular enzyme that carries out a response.

2 points

QUESTION 5

Which of the following is an example of signal amplification?

	a.	activation of an enzyme molecule
	b.	activation of a specific gene by a growth factor
	c.	Breakdown of many cAMP molecules
	d.	activation of 100 molecules by a single signal binding event

2 points

QUESTION 6

Consider a signal transduction pathway that utilizes cAMP as a second messenger to activate PKA (Protein Kinase A). Which of the following situations will result in the cellular response?

		The G protein releases GDP and binds to GTP
		The target protein (adenylyl cyclase) is inactive
		The regulatory subunits of PKA (Protein Kinase A) are bound to the catalytic subunits
		The appropriate G protein is bound to GDP

2 points

QUESTION 7

Which of the following is found in only some signal transduction pathways? [In other words, which is not found in all signal transduction pathways?]

		Receptor protein
		Extracellular signal molecule
		Intracellular signaling molecule
		Cellular response
		Effector protein

2 points

QUESTION 8

The enzyme that specifically catalyzes the conversion of ATP to cAMP is:

		Adenylyl phosphatase
		Adenylyl kinase
		Adenylyl dehydrogenase
		Adenylyl cyclase

2 points

QUESTION 9

If an animal cell suddenly lost the ability to produce GTP, what might happen to its signaling system?

		It would use ATP instead of GTP to activate and inactivate the G protein on the cytoplasmic side of the plasma membrane.
		It would not be able to activate and inactivate the G protein on the cytoplasmic side of the plasma membrane.
		It would employ a transduction pathway directly from an external messenger.
		It would be able to carry out reception and transduction but would not be able to respond to a signal.

2 points

QUESTION 10

A hormone signal is sent from the brain to other parts of the body via the bloodstream. Why do only certain cells respond to this signal?

		Hormones do not last long enough in the bloodstream to stimulate a cellular response
		Only cells that have a specific transcription factor gene will be able to respond to the signal
		Only cells in the immediate vicinity of the cell sending the signal will respond
		Only cells that have a receptor for the specific signal will be able to respond to it

cerisehedgehog846

BIOM 2000 Lecture Notes - Lecture 2: Acetylcholine, Choroid Plexus, Postganglionic Nerve Fibers

Document Summary

Get access

Related Documents

BIOM 2000 Lecture Notes - Perineurium, Axon Hillock, Sensory System

BIOM 2000 Lecture Notes - Phospholipid, Epineurium, Axon Hillock

BIOM 2000 Lecture Notes - Lecture 2: Endoneurium, Hypothalamus, Brainstem

Related Questions